This invention relates to an endoscopic instrument assembly or device and to an associated endoscopic surgical technique. This invention relates more particularly to an irrigation instrument for use in endoscopic surgery. This invention also relates to an associated endoscopic technique.
In endoscopic diagnostic investigations and surgery, fiber optic instruments are used to visually inspect internal parts of a patient's anatomy through small incisions or natural openings (mouth, anus) in the patient. Frequently, fluids are needed at the distal end of the endoscope to clean a transparent light receiving surface or to clear a site of blood, faeces or other organic debris to facilitate the transmission of optical radiation.
U.S. Pat. No. 5,279,542 discloses an endoscopic instrument comprising an elongate tube provided essentially along its entire length with a channel and further provided within a distal end region with a plurality of longitudinally and circumferentially spaced apertures communicating with the channel. A pressurized source of irrigation fluid is operatively connected to the tube for feeding fluid through the channel and out through the apertures with an essentially uniform radial distribution. The tube is thin enough to fit down the biopsy channel of an endoscope.
Although the instrument of U.S. Pat. No. 5,279,542 works to adequately clean an internal site for purposes of endoscopically investigating that site, the performance of endoscopic surgical operations at the site, for example, the taking of a biopsy or the removal of a polyp, are impeded by the disposition of the endoscopic spraying device in the biopsy channel of the endoscope. This problem is obviated where the endoscope is provided with more than one biopsy channel, either in the insertion tube itself or in a sheath attached to the tube. However, in conventional endoscopes having just one biopsy channel, the endoscopic spraying or cleaning device of U.S. Pat. No. 5,279,542 must be removed and another instrument inserted to take the biopsy or remove the polyp. Frequently, the endoscopic spraying or cleaning device must be reinserted, for purposes of cleaning other sites during the same endoscope examination procedure.